Method and apparatus for an implantable pulse generator with a stacked battery and capacitor

ABSTRACT

The present subject matter includes one embodiment of an apparatus, comprising: a battery including a plurality of flat battery layers disposed in a battery case, the battery case having a planar battery surface which has a battery perimeter; and a capacitor including a plurality of flat capacitor layers disposed in a capacitor case, the capacitor case having a planar capacitor surface which has a capacitor perimeter, the capacitor stacked with the battery such that the planar battery surface and the planar capacitor surface are adjacent, with the capacitor perimeter and the battery perimeter substantially coextensive; a hermetically sealed implantable housing having a first shell and a lid mated to the first shell at a first opening, the first opening sized for passage of the battery, the capacitor, and the programmable electronics, wherein the battery and the capacitor are disposed in the hermetically sealed implantable housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/117,952, filed Apr. 29, 2005, the specification of which is hereinincorporated by reference.

The following commonly assigned U.S. patents are related to the presentapplication and are incorporated herein by reference in their entirety:“High-Energy Capacitors for Implantable Defibrillators,” U.S. Pat. No.6,556,863, filed Oct. 2, 1998, issued Apr. 29, 2003; “Flat Capacitor foran Implantable Medical Device,” U.S. Pat. No. 6,699,265, filed Nov. 3,2000, issued Mar. 2, 2004. Additionally, the present application isrelated to the following commonly assigned U.S. Patent Publication whichis incorporated herein by reference in its entirety: “Method andApparatus for Single High Voltage Aluminum Capacitor Design,” Ser. No.60/588,905, filed on Jul. 16, 2004. Further, the present application isrelated to the following commonly assigned U.S. patent application whichis incorporated by reference in its entirety: “Batteries Including aFlat Plate Design,” U.S. patent application Ser. No. 10/360,551 filedFeb. 7, 2003, which claims the benefit under 35 U.S.C 119(e) of U.S.Provisional Application Ser. No. 60/437,537 filed Dec. 31, 2002.

TECHNICAL FIELD

This disclosure relates generally to batteries and capacitors, and moreparticularly, to method and apparatus for an implantable pulse generatorwith a stacked battery and capacitor.

BACKGROUND

There is an ever-increasing interest in making electronic devicesphysically smaller. Consequently, electrical components become morecompact as technologies are improved. However, such advances intechnology also bring about additional problems. One such probleminvolves efficient packaging of components.

Components such as batteries, capacitors, and various additionalelectronics are often packaged together in electrical devices. As such,there is a need in the art for improved packaging strategies.Improvement could be realized by an overall increase in the efficiencyof component packaging in existing devices. But improved systems must berobust and adaptable to various manufacturing processes.

SUMMARY

The above-mentioned problems and others not expressly discussed hereinare addressed by the present subject matter and will be understood byreading and studying this specification.

One embodiment of the present subject matter includes a method ofstacking flat battery layers into a battery stack; positioning thebattery stack in a battery case, the planar battery surface having abattery perimeter; stacking flat capacitor layers into a capacitorstack; positioning the capacitor stack in a capacitor case, the planarcapacitor surface having a capacitor perimeter; disposing the flatbattery case and the flat electrolytic capacitor case in stackedalignment in a housing for implantation such that the battery perimeterand the capacitor perimeter are substantially coextensive; andhermetically sealing the housing.

Additionally, one embodiment of the present subject matter includes abattery having a plurality of flat battery layers disposed in a batterycase, the battery case having a planar battery surface which has abattery perimeter; and a capacitor including a plurality of flatcapacitor layers disposed in a capacitor case, the capacitor case havinga planar capacitor surface which has a capacitor perimeter, thecapacitor stacked with the battery such that the planar battery surfaceand the planar capacitor surface are adjacent, with the capacitorperimeter and the battery perimeter substantially coextensive; and ahermetically sealed implantable housing having a first shell and a lidmated to the first shell at a first opening, the first opening sized forpassage of the battery and the capacitor, wherein the battery and thecapacitor are disposed in the hermetically sealed implantable housing.

One embodiment of the present subject matter includes an apparatushaving a hermetically sealed implantable device housing having a lidmated to an opening; programmable pulse generation electronics disposedin the hermetically sealed implantable device housing, the programmablepulse generation electronics sized for passage through the opening;battery means for powering the programmable pulse generationelectronics, the battery means sized for passage through the opening;and capacitor means electrically interconnected to the battery means,the capacitor means for powering the programmable pulse generationelectronics and sized for passage through the opening.

This Summary is an overview of some of the teachings of the presentapplication and not intended to be an exclusive or exhaustive treatmentof the present subject matter. Further details about the present subjectmatter are found in the detailed description and appended claims. Otheraspects will be apparent to persons skilled in the art upon reading andunderstanding the following detailed description and viewing thedrawings that form a part thereof, each of which are not to be taken ina limiting sense. The scope of the present invention is defined by theappended claims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view of a power source, according to one embodiment ofthe present subject matter.

FIG. 1B illustrates a partial cross section of a device housing, abattery, and a capacitor, according to one embodiment of the presentsubject matter.

FIG. 2 is a perspective view of a capacitor, according to one embodimentof the present subject matter.

FIG. 3 is a perspective view of a battery, according to one embodimentof the present subject matter.

FIG. 4 is a perspective view of a battery and a capacitor, according toone embodiment of the present subject matter.

FIG. 5 is a method for constructing a battery and capacitor powersource, according to one embodiment of the present subject matter.

DETAILED DESCRIPTION

The following detailed description of the present subject matter refersto subject matter in the accompanying drawings which show, by way ofillustration, specific aspects and embodiments in which the presentsubject matter may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice thepresent subject matter. References to “an”, “one”, or “various”embodiments in this disclosure are not necessarily to the sameembodiment, and such references contemplate more than one embodiment.The following detailed description is demonstrative and not to be takenin a limiting sense. The scope of the present subject matter is definedby the appended claims, along with the full scope of legal equivalentsto which such claims are entitled.

Implantable medical devices are now in wide use for treating a varietyof diseases. Cardiac rhythm management devices, as well as other typesof implantable medical devices, are powered by a battery and a capacitorcontained within the housing of the device. The size and shape of abattery which supplies sufficient power to operate the device is onefactor which affects how small and physiologically shaped the housing ofthe device can be made. This is true for the capacitor as well. Thepresent disclosure relates to a battery and capacitor and method fortheir construction, each suitable for use in an electronic device.Various embodiments are adapted for use in an implantable medicaldevice. Overall, the present subject matter affords designers morefreedom in packaging electronic device components into a housing.

FIG. 1A is a side view of a power source 100, according to oneembodiment of the present subject matter. In various embodiments, anexample battery 102 includes a contour 116, which allows for positioningthe battery 102 in various devices. For example, in various embodiments,battery 102 is shaped for placement in device adapted for chronicimplantation. Additionally, in various embodiments, the battery 102includes a feedthrough port 108, which is adapted for passage of one ormore conductors. In various embodiments, the conductors at thefeedthrough port 108 are connected to the battery anode. The batteryadditionally includes a feedthrough port 110 which, in variousembodiments, is connected to the battery cathode. In some embodiments, asingle feedthrough port is used instead of two feedthrough ports. Otherembodiments include one or more feedthrough ports and a backfill port.

In various embodiments, the example capacitor 104 includes a contour118, which allows for positioning the capacitor 104 in various devices.For example, in various embodiments, capacitor 104 is shaped forplacement in a device adapted for chronic implantation. Additionally, invarious embodiments, the capacitor 104 includes a feedthrough port 112,which is adapted for passage of one or more conductors. In variousembodiments, the conductors at the feedthrough port 112 comprise aportion of the anode of the capacitor. The capacitor additionallyincludes a feedthrough port 114 which, in various embodiments, isconnected to the battery cathode. In some embodiments, a singlefeedthrough port is used instead of two feedthrough ports. Otherembodiments include one or more feedthrough ports and a backfill port.

In various embodiments, a device housing into which a battery andcapacitor may be disposed has an interior. In some of these embodiments,the device interior has a first major interior face and a second majorinterior face. Battery and capacitor combinations can be shaped to mateto these faces. For example, in one embodiment, a battery face 120 isadapted for abutting an interior face of a housing. In some embodiments,the housing and the battery face 120 are separated from a housing by aninsulator. The capacitor includes a face 122 which also is adapted forabutting an interior surface of a housing. Sidewall 402 and sidewall 404are adapted for placement adjacent additional device components, invarious embodiments.

Various embodiments maintain a continuous surface from sidewall 402 tosidewall 404. In various embodiments, the seam 106 defined by theadjacent battery 102 and capacitor 104 extends along a continuoussurface. Thus, in various embodiments, the combined capacitor andbattery are adapted for space efficient placement in a housing. Invarious embodiments, the housing is only marginally larger than thecombined capacitor and battery so that the housing may accommodate thosecomponents. As such, various embodiments enable packaging additionaldevices in the housing adjacent the battery capacitor combination.

Battery 102 has a thickness T_(B), in various embodiments. In variousembodiments, the thickness is measured orthogonally, extending betweeninterface 106 and surface 120. Additionally, capacitor 104 has athickness T_(C), in various embodiments. The thickness is measuredorthogonally, extending between interface 106 and surface 122, invarious embodiments. In various embodiments, the thicknesses T_(B) andT_(C) are selectable to fill the volume of a device housing. Forexample, in one embodiment, the present subject matter creates an indexof a plurality of flat capacitors, the index created by measuring thethickness T_(C) of each flat capacitor and storing that thickness in afirst index. Additionally, in various embodiments, the present subjectmatter creates an index of a plurality of flat batteries, the indexcreated by measuring the thickness T_(B) of each flat battery andstoring that thickness in a second index. The present subject matterthan selects a battery and a capacitor having respective thicknessesT_(B), T_(C) selected to fill the volume of the targeted device housing.

FIG. 1B illustrates a partial cross section of a device housing 150, abattery 102, and a capacitor 104, according to one embodiment of thepresent subject matter. In various embodiments, distance D extendsbetween a first interior surface 152 for abutting a battery face 120,and a second interior surface 154 adapted for abutting surface 122. Invarious embodiments, the present subject matter selects a capacitor froma first index, and a battery from a second index, such that the combinedthickness of the battery and the capacitor substantially match thethickness D. Additionally, in various embodiments, the selection ofbattery thickness and capacitor thickness is made in light of thethickness of adhesive layer and/or insulative layers disposed betweenthe battery and the capacitor, and between these respectivesubcomponents and the device housing. In varying embodiments, the ratiobetween capacitor thickness and battery thickness is from about 7:1 toabout 1.5:1. In additional embodiment, the ratio between the capacitorthickness and the battery thickness is from about 6:1 to about 2:1.Other ratios are possible without departing from the scope of thepresent subject matter.

In various embodiments, indexing of battery thickness, capacitorthickness, battery perimeter, capacitor perimeter, and other powersource parameters is performed using a programmable computer. Thepresent subject matter is not limited to indexes managed by programmablecomputers, however, as other indexing systems are within the scope ofthe present subject matter.

FIG. 2 is a perspective view of a capacitor, according to one embodimentof the present subject matter. Substantially flat electrolyticcapacitors, in various examples, include a plurality of capacitor layersstacked together. In various embodiments, these stacks of capacitors areassembled into a capacitor case. Various cases are conductive ornonconductive. Some cases include feedthroughs through which conductorspass. The present subject matter includes, but is not limited to,embodiments disclosed on or around pages 12-37, 39, 41-140 of thefollowing related and commonly assigned Provisional U.S. patentapplication “Method and Apparatus for Single High Voltage AluminumCapacitor Design,” Ser. No. 60/588,905, filed on Jul. 16, 2004,incorporated herein by reference.

In various embodiments, the present subject matter includes a flatelectrolytic capacitor 104 with a planar capacitor surface 202. Invarious embodiments, the planar capacitor surface includes a capacitorperimeter. In various embodiments, the capacitor stack is adapted todeliver between 7.0 Joules/cubic centimeter and 8.5 Joules/cubiccentimeter. Some embodiments are adapted to deliver about 7.7Joules/cubic centimeter. In some embodiments, the anode has acapacitance of between approximately 0.70 and 0.85 microfarads persquare centimeter when charged at approximately 550 volts. In variousembodiments, these ranges are available at a voltage of between about410 volts to about 610 volts.

However, in some embodiments, the stack is disposed in a case, andlinked with other components, a state which affects energy density insome embodiments. For example, in one packaged embodiment, including acase and terminals, the energy density available ranges from about 5.3Joules per cubic centimeter of capacitor stack volume to about 6.3Joules per cubic centimeter of capacitor stack volume. Some embodimentsare adapted to deliver about 5.8 Joules. In various embodiments, theseranges are available at a voltage of between about 410 volts to about610 volts.

Although these ranges embody one example possible within the scope ofthe subject matter, the subject matter is not so limited, and othercapacitors without departing from the scope of the present subjectmatter.

FIG. 3 is a perspective view of a battery, according to one embodimentof the present subject matter. In various embodiments, the battery 102of the present subject matter is substantially flat. Substantially flatbatteries, in various examples, include a plurality of batteryelectrodes stacked together, and further assembled into a battery case.Various battery cases are conductive or nonconductive. Some batterycases include feedthroughs. In various embodiments, the battery casesinclude a planar battery surface 302. The present subject matterincludes, but is not limited to, embodiments disclosed at paragraphs0095-0110, 0136-0196, 0206-0258 of the following related and commonlyassigned U.S. patent application, “Batteries Including a Flat PlateDesign,” U.S. patent application Ser. No. 10/360,551, filed on Feb. 7,2003, incorporated herein by reference.

FIG. 4 is a perspective view of a battery and a capacitor, according toone embodiment of the present subject matter. In various embodiments,the present subject matter includes a power source 100 which has abattery 102 and a capacitor 104 mated at an interface 106, at which aplanar battery surface and a planar capacitor surface are substantiallycoextensive. As a result of alignment, various embodiments demonstratean overall envelope which is substantially continuous. Additionally, invarious embodiments, the battery 102 includes a feedthrough ports 108,110. Capacitor 104 includes feedthrough ports 112, 114, in variousembodiments.

Various capacitor embodiments include a capacitor sidewall 402, andvarious battery embodiments include a battery sidewall 404. Variousembodiments additionally include a battery face 120. A capacitor face isnot visible in the illustration due to the orientation of the figure. Invarious examples, each of these respective case features is planar. Whenplaced adjacent to one another, various embodiments include featureswhich form a substantially planar overall sidewall which is the sum ofeach of the individual surfaces. In various embodiments, the overallsurface is continuous. For example, sidewalls 402, 404 form a continuoussurface. A continuous surface may have a linear shape, or a curvilinearshape. Embodiments having a continuous overall sidewall are within thescope of the present subject matter, however, additional embodiments arepossible without departing from the scope of the scope of the presentsubject matter.

FIG. 5 is a method for constructing a battery and capacitor powersource, according to one embodiment of the present subject matter. Inone embodiment of the present subject matter, the process includesestablishing form factor and power capacity requirements for a powersource to be used in an implantable medical device 502. The embodimentincludes constructing a flat battery by stacking flat battery layersinto a battery stack and positioning the stack in a battery case with aplanar interface and a battery perimeter and battery thickness 504. Theembodiment further includes constructing a flat electrolytic capacitorby stacking flat capacitor layers into a capacitor stack and positioningthe stack in a capacitor case with a planar interface and a capacitorperimeter and capacitor thickness 506. The embodiment additionallyincludes stacking the flat battery and the flat electrolytic capacitorsuch that the battery perimeter and the capacitor perimeter aresubstantially coextensive 510. This embodiment is illustrative of thepresent subject matter, but it should be noted that other combinationsof steps, and additional steps, also lie within the scope of the presentsubject matter.

For example, in some embodiments, a battery thickness, batteryperimeter, capacitor thickness and capacitor perimeter are selectedbased on form factor and power capacity requirements for an implantablemedical device 508. Additionally, various method embodiments includemeasuring a ratio between battery thickness and capacitor thickness, andusing this ratio in selecting a battery and capacitor. A ratio is beestablished by known power requirements, in various embodiments. Anotherexample combines size requirements with power requirements in selectinga ratio. The ratio can be stored and used by a design process ormanufacturing process to discern the mechanical and electricalcomposition of a needed power source, in various embodiments.

In various embodiments, the present subject matter includes deliveringfrom the flat battery and the flat electrolytic capacitor from about1.25 Joules per Amp hour of battery capacity to about 50 Joules per amphour of battery capacity. In some of these embodiments, the flat batteryhas a battery capacity density of from about 0.23 amp hours per cubiccentimeter of flat battery to about 0.25 amp hours per cubic centimeterof flat battery. Battery capacity density is measured by dividing theamp-hour rating of the battery by the battery volume, in variousembodiments. The present subject matter includes, but is not limited to,embodiments disclosed at paragraphs 0095-0110, 0136-0196, 0206-0258 ofthe following related and commonly assigned U.S. Patent Publication,“Batteries Including a Flat Plate Design,” U.S. Patent Publication No.2004/0127952, filed on Feb. 7, 2003, incorporated herein by reference.

In additional embodiments, the flat electrolytic capacitor includes anenergy density of from about 4.65 joules per cubic centimeter of flatelectrolytic capacitor to 6.5 joules per cubic centimeter of flatelectrolytic capacitor. The present subject matter includes, but is notlimited to, embodiments disclosed on or around pages 12-37, 39, 41-140of the following related and commonly assigned Provisional U.S. patentapplication “Method and Apparatus for Single High Voltage AluminumCapacitor Design,” Ser. No. 60/588,905, filed on Jul. 16, 2004,incorporated herein by reference.

Various methods of the present subject matter benefit from selectingcapacitor stack layers and battery stack layers which are substantiallyparallel to their coextensive case interfaces. By constructing the powersource as such, various benefits are possible. For example, in oneembodiment, a single two-axis machine can position capacitor layers in astack, position the capacitor stack in a capacitor case, positionbattery layers in a stack, and position the battery stack in a batterycase. In one embodiment, the single two-axis machine is a pick-and-placemachine. This combination is provided for illustration, but othercombinations of these steps are possible, and additional steps are alsowithin the scope of the present subject matter.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiment shown. This application isintended to cover adaptations or variations of the present subjectmatter. It is to be understood that the above description is intended tobe illustrative, and not restrictive. Combinations of the aboveembodiments, and various embodiments, will be apparent to those of skillin the art upon reviewing the above description. The scope of thepresent subject matter should be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled.

1. A method, comprising: stacking flat battery layers into a batterystack; positioning the battery stack in a battery case having a batterythickness measured away from a planar battery surface, the planarbattery surface having a battery perimeter; stacking flat capacitorlayers into a capacitor stack; positioning the capacitor stack in acapacitor case having a capacitor thickness measured away from a planarcapacitor surface, the planar capacitor surface having a capacitorperimeter; disposing the flat battery case and the flat electrolyticcapacitor case in stacked alignment in a housing such that the batteryperimeter and the capacitor perimeter are substantially coextensive; andhermetically sealing the housing.